Ch. 5

Question 1

Problems assoc. with malnutrition?

Answer 1

MC immune deficiency; leads to infection

Question 2

Microflora within stomach?

Answer 2

Virtually sterile; some GPCs, some yeast

Question 3

Microflora within proximal small bowel?

Answer 3

10^5 bacteria, mostly GPCs

Question 4

Microflora within distal small bowel?

Answer 4

10^7 bacteria, GPCs, GPRs, GNRs

Question 5

Microflora within colon?

Answer 5

10^11 bacteria, almost all anaerobes, some GNRs, GPCs,

Question 6

Most common organism in GI tract?

Answer 6

Anaerobes; MC than aerobic bacteria in the colon (1,000:1)

Question 7

What makes bacteria anaerobic?

Answer 7

Needing a low-oxygen environment (lack superoxide dismutase and catalase, making them vulnerable to oxygen free radicals)

Question 8

MC anaerobe in the colon?

Answer 8

Bacteroides fragilis

Question 9

MC aerobic bacteria in colon?

Answer 9

E. Coli

Question 10

MC fever source within 48 hours?

Answer 10

Atelectasis

Question 11

MC fever source within 48 hours - 5 days?

Answer 11

UTI

Question 12

MC fever source after 5 days?

Answer 12

Wound infection

Question 13

MC cause of Gram (-) sepsis?

Answer 13

E. coli

Question 14

Pathophysiology of Gram (-) sepsis?

Answer 14

Endotoxin triggers the release of TNF-alpha (most potent stimulus; released from macrophages, triggers inflammation), activates complement, and activates coagulation cascade

Question 15

What is the cause of Gram (-) sepsis)

Answer 15

Release of endotoxin (lipopolysaccharide lipid A)

Question 16

Metabolic findings in Early gram (-) sepsis?

Answer 16

low insulin
elevated glucose (impaired utilization)

Question 17

Metabolic findings in Late gram (-) sepsis?

Answer 17

elevated insulin
elevated glucose (secondary to insulin resistance)

Question 18

What often occurs just before a patient becomes clinically septic?

Answer 18

Hyperglycemia

Question 19

What is the optimal glucose level in a septic patient?

Answer 19

80-120 mg/dL

Question 20

What are the signs of C. diff?

Answer 20

foul-smelling diarrhea; leukocytosis (often in 30-40’s); nursing home or ICU patients

Question 21

How to diagnose C. diff?

Answer 21

ELISA for toxin A

Question 22

Treatment for C. diff?

Answer 22

Oral - vamcomycin or Flagyl
IV - Flagyl
Fluid resuscitation
Stop other antibiotics or change them
Lactobacillus can also help

Question 23

Treatment of C. diff in pregnancy?

Answer 23

oral vancomycin ( no systemic absorption)

Question 24

What is fulminant pseudomembranous colitis? Treatment?

Answer 24

C. diff with severe sepsis, perforation

Tx: total colectomy with ileostomy

Question 25

What percentage of abdominal abscesses have anaerobes?

Answer 25

90%

Question 26

What percentage of abdominal abscesses have both anaerobic and aerobic bacteria?

Answer 26

80%

Question 27

How are abscesses treated?

Answer 27

Drainage

Question 28

When do abscesses normally occur following an operation?

Answer 28

7-10 days

Question 29

When are antibiotics indicated for abscesses?

Answer 29

Patients with diabetes, cellulitis, clinical signs of sepsis, fever, or who have bioprosthetic hardware (mechanical valves, hip replacements)

Question 30

Example of clean operation; percentage surgical site infection?

Answer 30

Hernia; 2%

Question 31

Example of clean contaminated operation; percentage surgical site infection?

Answer 31

elective colon resection with prepped bowel; 3-5%

Question 32

Example of contaminated operation; percentage surgical site infection?

Answer 32

gunshot wound to colon with repair; 5-10%

Question 33

Example of grossly contaminated operation; percentage surgical site infection?

Answer 33

abscess; 30%

Question 34

What is done to prevent surgical site infections?

Answer 34

Prophylactic antibiotics given within 1 hour of incision; stop within 24 hours of end operation time (except cardiac - stopped within 48 hours)

Question 35

MC organism involved in surgical site infections?

Answer 35

Staph aureus - coagulase (+) vs. Staph epidermidis - coagulase (-)

Question 36

What is released by Staph species that makes them stick around?

Answer 36

Exoslime (exopolysaccharide matrix)

Question 37

What is the MC GNR in surgical wound infections?

Answer 37

E. coli

Question 38

What is the MC anaerobe in surgical wound infections?

Answer 38

B. fragilis

Question 39

What is the concern if B. fragilis is recovered from tissue?

Answer 39

Indicates necrosis or abscess ( only grows in low redox state); also implies translocation from gut

Question 40

How many organisms needed for a wound infection?

Answer 40

>= 10^5 bacteria; less needed if a foreign body present

Question 41

What are some risk factors for wound infections?

Answer 41

``` long operations hematoma or seroma formation advanced age chronic disease (eg, COPD, liver/renal failure, DM) malnutrition immunosupressive drugs ```

Question 42

Considerations if have a surgical infection within 48 hours of procedure?

Answer 42

Injury to bowel - with a leak Invasive soft tissue infection - Clostridium perfringens and beta-hemolytic strep can present within hours post op ( produce endotoxins)

Question 43

MC infection in surgery patients?

Answer 43

UTI - biggest risk factor are urinary catheters - MC E. Coli (GNRs)

Question 44

What is the leading cause of infectious death after surgery?

Answer 44

Nosocomial pneumonia

Question 45

What is the biggest risk factor for nosocomial pneumonia following surgery?

Answer 45

Length of ventilation | Aspiration from duodenum thought to have a role

Question 46

What are the most common organisms in ICU PNA?

Answer 46

``` #1 Staph aureus #2 Pseudomonas #3 E. Coli ```

Question 47

What are the #1 class of organisms implicated in ICU PNA?

Answer 47

GNRs